The present invention relates to a loom, and more particularly to a loom having a back rest, a breast beam and a driving mechanism therefor for driving the warp yarn and fabric during the weaving operation.
In conventional looms, the winding of the woven goods on the cloth beam and the removal of warp from the warp beam are controlled independently of one another by separate devices. The winding of the woven goods on the cloth beam is controlled by a regulator with which the density of the weft can be selected. A letoff serves to maintain as constant as tension as possible in the warp running off of the warp beam. Essentially these devices have to perform the task of keeping the average peripheral speed of the warp and cloth beam constant, that is to say, to adapt the average speed of rotation of these beams to the diameter of the yarn and fabric wound thereon which alters as the weaving process progresses.
As is known, this can be achieved, for example by regulating the rate of action of the cloth beam drive, or by utilizing a braking force or by regulating the magnitude of the braking force acting on the warp beam depending on the diameter of the wound goods, or by sensing the warp remaining on the warp beam. Such devices are generally expensive in construction. In addition, this mode of regulation requires powerful drive and bearing members for the cloth beam and warp beam in order that the considerable tensions of the warp and woven goods which occur can be taken up satisfactorily.